Thermo-electric fire-alarm.



H. BARDITZKY. THERMO ELECTRIC FIRE ALARM.

APPLICATION FILED MAY 14. 1904.

N0 MODEL.

PATENTED OCT. 18, 1904.

WITNESSES.-

"a l. i H 11ml [/VVENTOR Alforjney No. 772,772. I

UNITED STATES Patented October 18, 1904.

PATENT OFFICE.

HERMANBARDITZKY, or MEMPHIS, TENNESSEE, ASSIGNOR or ONE-HALF TO FRANK SYBILLA, or OHATTANOOGA, TENNESSEE.

' "II'HIERMO-ELLECTRIC FIRE-ALARM.

SPECIFICATION forming part of Letters Patent No. 772,772, dated October 18, 1904. Application filed May 14, 1904. Serial No. 208,032. (No model.)

To all, whom, it may concern:

Be it known that I, HERMAN BARDITZKY, a citizen of the United States, residing at Memphis, in the county of Shelby and State of Tennessee, have invented certain new and useful Improvements in Thermo-Electric Fire- Alarms, of which the following is a specification.

My invention relates generally to firealar'ms, and more particularly to that class of fire-alarms which comprises a belllor other alarm-sounder included inlan electric circuit which is'norrnally open andmay be closed to 1 operate the alarm by the operation of a thermostat also located in the circuit and placed .or-secuied in any suitable position at which there is danger of fire.

The general object of the invention is to improve the construction of such'fire-alarms and insure their positive and reliable operation, the special object being to provide'a thermostat of improved construction and operation for such use; and with such objects in view the invention consists in the improved construction, arrangement, and combination of parts hereinafter fullydescribed and afte'rward specifically claimed.

In order to enable others skilled in the art to which my invention most nearly appertains to make and use the same, I will now proceed to fully describe its construction and operation in connection with the accompanying drawings, which illustrate a device constructed according to my invention and adapted to be secured to the ceiling of 'a room or other overhead support, although without altering the construction the device is adapted to be reversed in position and supported loosely upon a table or shelf or to be secured to a Wall or other upright support.

In the drawings, Figure 1 represents a side elevation; Fig. 2, a vertical longitudinal sec tion; Fig. 3, a bottom plan View, and Fig. i an elevation of the right-hand end.

Like reference characters mark the same parts in all of the figures of the drawings.

Referring specifically to the drawings, 1 indicates a plate or bar of metal of which the coefficient of expansibility under 'the influence of heat is as near zero as possible, a newly-discovered alloy ofiead and antimony being probably preferable because of its al- .most unnoticeable expansion under such influence.

2 indicates a thin bar or needle of highlyexpansible metal, (aluminium having been used by me with good results) which is supported from the bar 1 by means of brackets 3 and 4, which are secured to the bar 1 by bolts 5, 6, 7, and 8, the needle being slidably mounted in an opening in the bracket 4 and being threaded at 9 to engage a threaded opening in the bracket 3. The rear,end 10 of the needle 2 is made of other than circular shape, as shown at 10 in Fig. i, to receive a toothed wheel 11, bymeansof which the needle may be turned to adjust it longitudinally in the bracket 3. A spring-pawl 12 is secured under the head of the bolt 5, its outer end being.

tion, the pawl sliding over the teeth during its turning.

13 indicates a bracket secured to the bar 1 by means of bolts 14. and 15 and provided with a smooth opening in line with the needle 2, in which opening is loosely placed a" plug 16, normally held yieldingly therein by means of a-spring 1T, secured under the head of the bolt 14. f r

18 indicates a conducting-wire secured un-' der the head of the bolt 15, and 19 a similar wire secured-under the head of the bolt 6, the

former being in electrical contact with the bracket 13, but insulated from the bolt 15,

and'the latter in electrical contact with the bracket 3, but insulated from the bolt 6, and

the wires leading, respectively, from the poles of any suitable source of electricity in the circuit-of which is placed an electric bell or other electric alarm-sounding device. The brackets are suitably insulated frofn the bar 1, the bolts from the brackets, and the pawl 12 and spring 17 fromgthebolts 5 and 1- The needle 2 is adjusted at normal temperature by turning the wheel 11 to bring its point 20 to a position at a suitable-distance from the plug 16, such distance being regulated so as to cause the point to contact with the plug when the needle is exposed to a predetermined high degree of temperature, which degree may, if desired, be indicated by graduations on theouter surface of the'wheel;

Nhen by reason of fire breaking out in .the apartment this predetermined degree of temperature is reached, the contact of the point 20 and plug 16 closes the electric circuit and causes an alarm to be sounded, the current passing through wire 18, bracket 13, plug 16, needle 2, bracket 3, and wire 19. Should the temperature rise above the predetermined .de-

gree, the spring 17 will permit the plug 16 to yield in the direction of the expansion of the needle 2, and thus prevent the'bending of the needle or the breaking of any of-the parts.

Thebar 1', as before stated, has a very low coiiicient oi" expansibility' and as a consequence detracts but little or nothing from the expansion of the-needle 2 by reason of its openings 21, Fig. 3, through which nails,v

screws, bolts, or other suitable fasteniugs may be passed to secure it in position.

By practical experiments 1 have found that this device is entirely reliable in operation, and while 1 have described the construction and arrangement of thevarious parts in minute detail it will be obvious to those skilled in the art that slight changes therein or variation therefrom may be made without departing from the spirit or scope or my invention.

Having thus fully described my invention, What Iclaim as new, and desire to secure by Letters Patent of the United States, is-

1. In a thermostat the combination of a bar or support, a bracket secured thereto, a con tact-plug yieldingly mounted in and electrically connected with the bracket, a second bracket secured to the bar and insulated from the first bracket, and a longitudinally expam sible needle adjustably secured in and'electrically connected with the second bracket in line with and adapted to contact with the plug when expanded, one bracket and the'plug'being in' circuit with one pole and the other bracket and the needle with the opposite pole of the source of electricity, substantially as described.

2, in a thermostat, the combination of a bar having a low coefii'cient of expansibility, three brackets projecting therefrom in line with each other, one having a threaded opening and the other two smooth openings in line therewith, a metal needle having a high coefiicient of expanslbility engaging in the threaded opening and slidably mounted in one of thesmooth openings, and a contact-plug yieldingly mounted in the other smooth opening, substantially as described.

- 3. in a thermostat, the combination of a bar having a low coeificient of expansibility, two

brackets adjacent thereto at a distance from each other and insulatedi rom the bar, bolts passing through the brackets into the bar and insulated from the brackets and the bar, a con ducting-wire connected up with each bracket, a nietal needle having a high coefiicient of expansibility adjustably mounted in and in electrical contact with one of the brackets, and a contact -plug mounted in the other bracket in electrical contact therewith and in line with the needle,substantiallyas described.

4. In a thermostat, the combination ofa bar having a low cociiicicntot' expansibility, three brackets adjacent theretont different points in its length and insulated therefrom, bolts passing through the brackctsinto the bar and insulated from the brackets, a metal needle threaded through one of the outer brackets and passed slidably through the middle bracket,

a plug slidably-inounted in the other outer bracket in line with the needle, an insulated spring secured by one of the bolts and pressing the plugyieldingly in the direction of the needle, a toothed wheel secured on the outer end of the needic, an insulated spring-pawl secured by one of the bolts andengagingthe toothed wheel, and insulated wires secured by two of the bolts in electrical contact with the two outer brackets, substantially as de-' scribed. n Intestimony whereof I aiiix my signature in presence of two witnesses. 

